Field of the Invention
The present invention relates generally to a fastening device, and more particularly to a fastening device including a tubular sleeve member for mounting on a tube or for immobilizing telescopically connected first and second tubes. The fastening device further includes at least one first fixing element mounted on the sleeve member such that tightening of the first fixing element relative to the tubular sleeve member in a first section results in a narrowing notch formed in the sleeve member but permits the tube to move axially in the sleeve member and further tightening of the first fixing element relative to the sleeve member in a second section after the first section results in pressing of the sleeve member against the tube, thereby immobilizing the sleeve member and the tube.
The Prior Arts
A conventional fastening device, such as a C-shaped clamp member, for holding an article, is mounted on a tube via a fastener member. However, during loosening of the fastener member relative to the tube, a notch of the clamp member is not sufficiently large enough to permit smooth sliding of the clamp member relative to the tube or is too wide and results in wobbling of the same relative to the tube.
Another conventional fastening device currently available is generally used in a tripod, such as a camera tripod, for telescopically connecting at least two tubes (first and second tubes). The fastening device has different configuration and structures and includes a conventional sleeve member for sleeving around the tubes. A fastener knob is generally used to tighten the sleeve member so as to tightly abut against the tubes, thereby preventing the tubes from disengaging relative to each other. However, it is noted that the conventional sleeve member has only the clamping structure but its clamping strength thereof cannot be adjusted in advance.
In short, the conventional sleeve member for telescopically connecting two tubes may lead to disengagement among them in the time of long use and in wobbling of relative to each other or a notch of the clamp member is not sufficiently large enough to permit smooth sliding of the tubes relative to each other.